A solution is saturated with both AgCl (K_sp = 1.8 x 10^-10) and AgBr (K_sp = 5.0 x 10^-13). Find [Br^-] in units of 10^-8 mol L^-1 (two decimals).

JEE Advanced levelNumerical answerDifficulty 3 of 3ie206

A solution is saturated with both $AgCl$ ( $K_{s p} = 1.8 \times 1 0^{- 10}$ ) and $AgBr$ ( $K_{s p} = 5.0 \times 1 0^{- 13}$ ). Find $[Br X^{-}]$ in units of $1 0^{- 8} mol L^{- 1}$ (two decimals).

Numerical answer type, answer in x 10^-8 mol/L, tolerance 0.03.

Shared

Ag X^{+}

obeys

[Ag X^{+}]^{2} = K_{1} + K_{2}

, so

[Ag X^{+}] = 1.3 \times 1 0^{- 5} M

. Then

[Br X^{-}] = 5.0 \times 1 0^{- 13} /1.3 \times 1 0^{- 5} = 3.7 \times 1 0^{- 8} M